In general, an air conditioning system (HVAC: heating, ventilating, and air conditioning) for a vehicle means an air adjusting device that may maintain temperature, humidity, and cleanliness of air in the interior of the vehicle.
The HVAC may circulate cold air into the interior of the vehicle using processes of compressing, condensing, expanding, and evaporating a refrigerant in the vehicle, and may circulate warm air into the interior of the vehicle using a coolant heated by an engine.
The HVAC has an air vent that discharges air to the interior of the vehicle, and the air vent is installed in an instrument panel adjacent to a driver seat.
In the air vent for a vehicle in the related art, a damper, which is manually or automatically operated, is installed in a duct, which is an air flow path, in order to adjust a direction, a velocity, and an amount of air that is discharged in accordance with an operation of a heater or an air conditioner. Further, wings, which are operated in conjunction with the damper to adjust an air direction, are also installed.
The damper and the wings are installed in the duct, which is an air flow path, in a horizontal direction or a vertical direction, respectively, and vice versa, and the wings adjust a direction of air discharged through the duct, and shut off the discharge of air by closing an exit of the duct. In this case, when the wings are closed, the damper linked to the wings shuts off a passage inside the duct, thereby shutting off air discharged to the exit of the duct.
Recently, in order to reduce production costs for the air vent and simplify a structure of the air vent, a wing-close-type air vent, which does not use the damper and shuts off discharge of air only by using the wings, is used.
The wing-close-type air vent has front wings and rear wings that are installed in the discharge port of the duct in the horizontal and vertical directions or in the vertical and horizontal directions, and discharge of air is shut off as wings provided in the front wings and the rear wings overlap each other. Further, a direction, a velocity, and an amount of air discharged through the air vent are adjusted by controlling the front wings and the rear wings.
The wing-close-type air vent has predetermined gaps between the respective wings, which constitute the front wings and the rear wings, in order to prevent the wings from colliding with each other while the wings overlap each other. While the front wings and the rear wings are closed, air passing over the front wings and the rear wings generates a whistling noise similar to sound of a whistle caused by air resistance at the gaps between the wings. In addition, in a case in which there is no gap between the wings, a level of the whistling noise is further increased, and in a case in which the gap between the wings is greater than a predetermined gap, a large amount of air leaks occurs because discharge of air cannot be appropriately shut off